JPS6365447B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a machine tool that processes a workpiece by rotating a tool and reciprocating the tool relative to the workpiece.

BACKGROUND ART Conventionally, in a machine tool such as a drilling machine, before cutting, the rotational speed and feed rate are adjusted in advance to suit the machining process. The rotational speed was adjusted by checking the rotational speed of the electric motor, checking the reduction ratio of the reduction pulley, and calculating the rotational speed of the main shaft relative to the rotational speed of the electric motor. Therefore, the work was extremely troublesome.

Further, the feed rate is adjusted by actually moving the tool while adjusting the feed adjustment device, and determining the feed rate by the operator's sense of the tool moving speed to determine a predetermined feed rate. Therefore, like the adjustment described above, the work is not only very troublesome, but also cannot be performed accurately.

Purpose The purpose of this invention was to solve the above problems, and the purpose is to accurately and easily confirm the rotation speed when adjusting the rotation speed of a tool before machining. In addition to providing a machine tool that is capable of The purpose of the present invention is to provide a machine tool in which the completion of machining by a tool can be seen at a glance.

Embodiment Hereinafter, an embodiment in which the present invention is embodied in a drilling machine will be described based on the drawings.

In FIG. 1, a pulley 1a attached to a three-phase induction motor (hereinafter referred to as motor) 1 serving as a rotational drive device is drivingly connected to a pulley 2b attached to a base end shaft portion 2a of a transmission spring 2 via a belt B. has been done. A base end of a spline shaft 3 disposed on the same axis as the shaft 2a of the spring 2 is connected and fixed to the distal end of the transmission spring 2, and the rotational force of the motor 1 is transferred to the spline shaft 3. to communicate. A drill 6 as a tool is attached to the tip of the main shaft 4 via a chuck 5, and a cylindrical portion 7 is provided at the base end into which the spline shaft 3 is fitted so as to be movable only in the axial direction.

The main shaft cylinder 8 supports the main shaft 4 rotatably and immovably in the axial direction, and has a piston 9 on its outer periphery.
is attached. The air cylinder 10 has the piston 9 inserted therein to constitute a reciprocating drive device, and a first air cylinder chamber 11 and a second air cylinder chamber 12 are provided with the piston 9 as a boundary. The electromagnetic valve 13 is switched and controlled by an electric control circuit to be described later, and when the air from the air pump 14 is supplied to the first air cylinder chamber 11 and the air from the second air cylinder chamber 12 is discharged by the silencer 16, the piston 9, that is, the main shaft The cylinder 8 is moved forward, and when the air from the air pump 14 is supplied to the second air cylinder chamber 12 and the air in the first air cylinder chamber 11 is discharged by the silencer 16, the main shaft cylinder 8 is moved backward.

Therefore, rotational force is applied to the drill 6 by the motor 1, and reciprocating motion is performed by switching the electromagnetic valve 13. A feed control device, which will be described later, is provided above the air cylinder 10, and a portion of the feed control device is engaged when the main shaft cylinder 8 moves forward, thereby controlling the feed speed.

The drilling operation using this drilling machine is performed as follows. That is, as shown in Figure 2,
First, the drill 6 at the origin P0 rotates and moves forward toward the workpiece 17 at a high speed, and
At a first switching point P1 immediately before reaching , the forward speed is switched down by the feed control device to a speed optimal for drilling and cutting, and drilling and cutting is started at that speed. When a certain level of cutting resistance (cutting torque) is applied to the main shaft 4 holding the drill 6 due to the drilling, the drill 6 moves back at a high speed to the return position R near the origin position P0. Then, after moving forward at a high speed from the backward movement position R to the second switching point P2 just before reaching the bottom of the hole drilled for the first time, the speed is reduced to the optimum speed for drilling and cutting in the same manner as above. Then, drilling and cutting are performed again, and when a cutting resistance of a certain level or more is applied to the drill 6, the drill 6 moves back to the return position R at a high speed.

In this way, the above operations are repeated until a predetermined depth D is reached, that is, until the end of machining. When drilling and cutting are performed to the required depth D, the drill 6 returns to the origin position P0. The drilling operation is completed by moving back at a high speed.

Next, a torque detection device for detecting the driving torque applied to the transmission spring 2 will be explained.

In FIG. 1, a rotating disk 18 is fixed to the base end of the spline shaft 3 and rotates together with the spline shaft 3. In this embodiment, as shown in FIG. 3, the rotating disk 18 has 71 pieces at equal angular intervals of 1.5 degrees in the rotational direction of the disk 18, and thereafter the positions are arranged at intervals that increase exponentially. In addition, 89 slits 19 as detected portions are transparently provided on the same circumference centering on the axis of the spline shaft 3, and approximately 131 in the rotational direction of the disc 18 with respect to the slits 19. Fourteen fan-shaped through holes 20 are continuously provided on the same circumference about the axis of the spline shaft 3 from a position displaced by an angle of .degree.

The shielding plate 21 is fixed to the shaft portion 2a of the transmission spring 2 so as to face the rotating disk 18, and rotates together with the shaft portion 2a. In this embodiment, as shown in FIG. 4, the shielding plate 21 includes a slit shielding portion 22 that shields the slit 19 when facing the rotating disk 18, and a through hole that shields the through hole 20. A shielding portion 23 and a reference hole 24 facing the transparent position of the through hole 20 are formed. Also, a shielding plate 21 is provided with respect to the rotating disk 18.
is arranged so that when the shaft portion 2a is in a stopped state, it is at the relative position shown by the dashed line in FIG. .

The angular displacement detection photocoupler 25 and the timing photocoupler 26 are respectively disposed on a support member (not shown) in the machine frame (not shown) as shown in FIG. The passage of the rotating disk 18 through the slit 19 is detected, and the timing photocoupler 26 is connected to the reference hole 2 of the shielding plate 21.
4 is detected. Note that even if the reference hole 24 passes through the timing photocoupler 26 in a state shown by the dashed line in FIG. It is now possible to do so.

Now, when the motor 1 is driven to rotate and the main shaft 4, that is, the drill 6 is rotated with no load, the elastic force of the transmission spring 2 causes the shielding plate to
1 is balanced with a slight relative angular displacement (eight slits in this example) in the rotational direction with respect to the rotating disk 18, and has the same rotational speed as the same disk 18 without causing any relative angular displacement. It is rotated by Therefore,
In this state, the photocoupler 25 for angular displacement detection is 40 (=32+8) every time the rotating disk 18 makes one rotation.
40 pulse signals equal to the number of slits 19 passed through are outputted as driving torque applied to the transmission spring 2 in the no-load state.

Next, when a load torque (for example, cutting resistance applied to the drill 6) is applied to the transmission spring 2, the load torque causes the shielding plate 21 to move in the rotational direction relative to the rotating disk 18 in proportion to the magnitude of the torque. Due to the relative angular displacement, the angular displacement [k]
The slit 19 is newly exposed from the slit shielding portion 22 of the shielding plate 21. Therefore, the angular displacement detection photocoupler 25 detects the number (=40
+k) passing through the slit 19 is detected, and a number of pulse signals equal to the number of pulse signals passed through are outputted as driving torque in a loaded state.

On the other hand, since the timing photocoupler 26 also displaces the reference hole 24 with the displacement of the shielding plate 21, the angular displacement detection photocoupler 25 detects the passing of the reference hole 24 before the slit 19 starts passing, and the timing Outputs a pulse signal. Therefore, the timing photocoupler 26 outputs a timing pulse signal before the angular displacement detection photocoupler 25 detects passage of the slit 19 for each rotation.

Next, a description will be given of a control device that reduces the forward speed of the drill 6 to a speed optimal for drilling when the drill 6 moves forward to a position immediately before cutting.

The hydraulic cylinder 27 is arranged near the air cylinder 10, and a piston rod 27 is installed in the chamber thereof.
A coil spring 27b is disposed to constantly move rearward. The driven shaft 28 is fixed to the base end of the piston rod 27a, and a one-way clutch 29 is mounted behind it. The one-way clutch 29 allows the driven shaft 28 to move forward and restricts its backward movement. or,
The driven shaft 28 has an abutting piece 7a fixed to the cylindrical portion 7.
The forked portions at the distal ends of the two are fitted together, so that the abutment piece 7a moves forward along the driven shaft 28 as the main shaft cylinder 8 moves forward. When the forked portion of the abutting piece 7a abuts against the base end surface of the piston rod 27a, the abutting piece 7a moves the piston rod 27a forward.

A flow rate control valve 30 and a check valve CH are disposed on the front end side of the hydraulic cylinder 27.
As the piston rod 27a is moved forward, the pressure oil in the hydraulic cylinder 27 is discharged into the tank T while the flow rate is adjusted and regulated by the flow rate control valve 30. The forward movement speed of the piston rod 27a is limited by the throttling action of the flow control valve 30. Therefore, the main shaft cylinder 8 moves forward from the origin position P0 together with the main shaft supporting the drill 6, and the contact piece 7
After the piston rod 27a engages with the piston rod 27a, the forward movement speed of the main shaft cylinder 8 is switched down. For this reason,
The position of the drill 6 when the contact piece 7a engages with the piston rod 27a is the first switching point P1 shown in FIG. Then, cutting is performed at the optimum forward speed for cutting, and when a cutting force of more than a certain level is applied to the drill 6 during the cutting process, the drill 6 returns to the backward movement position R at a high speed. move. At this time, the piston rod 27a attempts to move rearward due to the coil spring 27b, but its movement is restricted by the one-way clutch 29. Therefore, when the drill 6 starts forward movement again from the backward movement position R, the position where the contact piece 7a engages with the piston rod 27a is immediately before the drill 6 performs cutting, that is, the second switching point P2 shown in FIG. corresponds to the position of

Origin position detection switch SW1, double movement position detection switch SW2, and machining end detection switch SW3
are each constituted by a micro switch, and are adapted to be turned on by engaging with an operating piece 7b fixed to the cylindrical portion 7, which moves with the reciprocation of the main shaft cylinder 8. And the home position detection switch SW
1 is turned on by the action of the actuating piece 7b when the drill 6 is at the home position P0, and the double movement position detection switch SW2 is turned on by the action of the actuating piece 7b when the drill 6 is at the double movement position R. Further, the machining end detection switch SW3 is arranged so that it is turned on by the action of the actuating piece 7b when the drill 6 reaches the machining end end (when it moves forward to a preset required depth D). has been done.

Next, a control circuit for driving and controlling the drilling machine configured as described above will be explained with reference to FIG.

In FIG. 6, a central processing unit (hereinafter referred to as CPU) 31 as a control means is a read-only program memory (hereinafter referred to as ROM) in which program data for controlling the drilling machine and other various data are stored. )
32, and a readable and writable memory (Random Access
Memory (hereinafter referred to as RAM) 33 constitutes an arithmetic and control unit. The start switch 34 is provided at a predetermined location on the drilling machine.
By pressing , the activation signal SG1 is output to the CPU 31 via the I/O port 35. Then, in response to this activation signal SG1, the CPU 31
Motor drive circuit 3 via I/O port 36
A drive control signal is output to 7 to rotate the motor 1. An emergency return switch 38 is provided at a predetermined location on the drilling machine, and when the switch 38 is pressed, a reset signal SG2 is output to the reset terminal of the CPU 31. The CPU 31 is adapted to return to its initial state in response to this reset signal SG2.

The origin position detection circuit 39 is composed of the origin position detection switch SW1, etc., and when the drill 6 is at the origin position P0 shown in FIG.
3 is output to the CPU 31 via the I/O port 35. The machining end detection circuit 40 is composed of the machining end detection switch SW3, etc., and detects when the drill 6 has moved forward to a preset required depth D relative to the workpiece 17 (when it has reached the cutting end position). ), end position signal SG4 I/O
It is configured to output to the CPU 31 via the port 35. The double-movement position detection circuit 41 is composed of the double-movement position detection switch SW2, etc., and when the drill 6 is at the double-movement position R shown in FIG. CPU31
It is now output to .

The drive torque detection circuit 42 includes the angular displacement detection photocoupler 25, the timing photocoupler 26, and a counter (not shown) that counts the pulse signal from the photocoupler 25 every time the rotating disk 18 rotates once. , detects the driving torque and outputs it to the CPU 31. The step torque value setter 43 is provided at a predetermined location on the drilling machine, and is used to set the maximum permissible cutting resistance standard for the cutting force applied to the drill 6 when the drill 6 used in the drilling machine is changed from forward motion to backward motion by an operator's operation. The value [X1] can be set appropriately, and the set resistance reference value [X1] is output to the CPU 31.

The drill breakage value setter 44 is provided at a predetermined location on the drilling machine, and is used to set a breakage reference value [Q] for the CPU 31 to determine whether or not the drill 6 has broken, by an operator's operation. The set breakage reference value [Q] is output to the CPU 31.

The valve drive circuit 45 is configured to switch and operate the electromagnetic valve 13 based on a drive control signal from the CPU 31.
to move forward and backward. The display device 46 includes 10 display sections 46a to 4 arranged at predetermined locations on the drilling machine.
6j, and these display sections 46a to 46j are controlled to light up and blink based on a drive control signal output from the CPU 31 to the display drive circuit 47.

The one-rotation detection circuit 48 inputs the on/off signal from the timing photocoupler 26, and outputs a pulse signal SG6 each time the rotating disk 18 makes one rotation, that is, each time the drill 6 makes one rotation. The counter 49 inputs the pulse signal SG6 from the one rotation detection circuit 48 via the I/O port 35,
Count the number and write the count value to the same port 3.
5 to the CPU 31. Further, the counter 49 is reset by a reset signal SG7 outputted from the CPU 31 via the I/O port 35.

A single-acting rotation operation switch 50 is provided at a predetermined location on the drilling machine, and when the switch 50 is pressed, a single-acting rotation signal SG8 is outputted to the CPU 31 via the I/O port 35. And CPU31
In response to this single-acting rotation signal SG8, a drive control signal is output to the motor drive circuit 37 via the I/O port 36 to rotate the motor 1.

A single-acting feed operation switch 51 is provided at a predetermined location on the drilling machine, and when the switch 51 is pressed, a single-acting feed signal SG9 is output to the CPU 31 via the I/O port 35. And CPU31
outputs a drive control signal to the valve drive circuit 45 via the I/O port 36 in response to the single-acting feed signal SG9, thereby switching the electromagnetic valve 13.

The step counter 52 controls the CPU 3 based on the double motion position signal SG5 from the double motion position detection circuit 41.
The number of steps of the drill 6 is counted based on the count signal output from the drill bit 1, and the value is displayed on the display device 53.

Next, the operation of the drilling machine configured as described above will be explained with reference to flowcharts of the arithmetic processing operations of the CPU 31 shown in FIGS. 7 and 8.

When the operator turns on the power switch (not shown) from the state where the drill 6 is now at the home position P0,
The CPU 31 first checks whether the drill 6 is at the origin position P0. At this time, when the origin position signal SG3 from the origin position detection circuit 39 is not output even though the drill 6 is at the origin position P0, the CPU 31 waits for 0.1 seconds and then checks whether the origin position signal SG3 is output again. Check and
Then, after checking that the same signal SG3 is not output, it waits for 0.1 second again. To be sure, the CPU 31 checks 100 times whether or not the origin position signal SG3 has been output, and then sends the display drive circuit 47 to the first and second display sections 46a from the left,
The valve drive circuit 45 outputs a display control signal for blinking the drill bit 46b and also outputs a drive control signal for returning the drill 6 to the home position P0.
Additionally, a drive control signal for stopping the rotation of the drill 6 is output to the motor drive circuit 37.
Then, the CPU 31 waits for the repair of the home position detection circuit 39 to be completed and for the emergency return switch 38 to be operated.

When the home position detection circuit 39 has been repaired and the emergency return switch 38 is pressed, the CPU 31 responds to the reset signal SG2 from the emergency return switch 38 to turn off the display sections 46a and 46b and reset each circuit. After outputting the output signal to each circuit, it returns to the initial state.

Next, the CPU 31 checks whether the drill 6 is at the origin position P0, and when checking that the drill 6 is at the origin position P0, determines whether the end position signal SG4 is output from the machining end detection circuit 40. Check. That is, it is checked here whether or not the machining end detection circuit 40 is out of order. Then, the drill 6 is at the origin position P
If the end position signal SG4 is output even though the position is 0, the CPU 31 outputs the end position signal again.
Detects the presence or absence of SG4. Then, to be sure, the CPU 31 checks 100 times that the end position signal SG4 is output, and then sends the display drive circuit 47 to the third and fourth display sections 46 from the left.
The valve drive circuit 4 outputs a display control signal to blink c and 46d, and also outputs a drive control signal to return the drill 6 to the home position P0.
5, a drive control signal for stopping the rotation of the drill 6 is output to the motor drive circuit 37. Then, the CPU 31 waits for the completion of repair of the termination end detection circuit 40 and the operation of the emergency return switch 38.

When the machining end detection circuit 40 has been repaired and the emergency return switch 38 is pressed, the CPU 31 responds to the reset signal SG2 from the emergency return switch 38 to turn off the display sections 46c and 46d and reset each circuit. After outputting the output signal to each circuit, it returns to the initial state.

Therefore, at this stage, the operator should check the display parts 46a, 4
When 6b flashes, it can be immediately confirmed that the origin detection circuit 39 is malfunctioning, and when the display parts 46c and 46d flash, it can be immediately confirmed that the machining end detection circuit 40 is malfunctioning. Accidents that may occur due to malfunctions of the detection circuits 39 and 40 during processing can be prevented.

After checking that the origin and machining end detection circuits 39 and 40 are operating normally, the CPU 31 waits for the single-acting feed operation switch 51, the single-acting rotation operation switch 50, or the start switch 34 to be operated.

Now, in order to adjust the feed speed of the drill 6, that is, the forward speed, before cutting, the operator presses the single-acting feed operation switch 51, and the single-acting feed signal SG9 is sent to the CPU.
31. The CPU 31 responds to this signal SG9 and sends the same signal 100 times to be sure.
Check whether SG9 is output. Next, the CPU 31 once turns off all signals output to each circuit, and then outputs a drive control signal for moving the drill 6 forward to the valve drive circuit 45 in order to switch only the electromagnetic valve 13.

At the same time as the drill 6 starts moving forward, the CPU 31
waits for 0.2 seconds after causing the display drive circuit 47 to output a display control signal for lighting the display section 46a. After checking that the drill 6 has not moved forward to the machining end end after 0.2 seconds have elapsed, that is, that the end position signal SG4 has not been output from the machining end detection circuit 40, the rightmost display section 46j is Check if it is lit.
At this point, the display section 46a is lit, so
The CPU 31 outputs a display control signal to the display drive circuit 47 for turning off the display section 46a and turning on the display section 46b on the right thereof, and then waits for 0.2 seconds again. In a state where the drill 6 has not reached the machining end end, the CPU 31 repeats the same operation as described above and causes the display sections 46a to 46j to turn on sequentially from left to right. Then, when 2 seconds have passed, that is, when the rightmost display section 46j lights up for 0.2 seconds, the CPU 31
The left end display section 46a is turned on again, and the same operation as described above is repeated many times until the drill 6 reaches the machining end position.

Then, the drill 6 eventually reaches the machining end position and the machining end detection circuit 40 sends a double-movement position signal SG.
When 5 is output, the CPU 31 causes the display part that is lit at that time to flash and operates the drill 6.
Return to the origin position. Therefore, the operator can determine the forward movement speed by knowing which display section is lit from the left and how many times it has been lit. That is, for example, when the drill 6 reaches the machining end when the display section 46j is lit for the fifth time, the drill 6 will move from the origin position P0 to the machining end in 10 seconds (=0.2×10
×5) That's what it took. Based on this feed rate, when the operator wants to increase or decrease the feed rate, the operator can easily and accurately adjust the required forward movement speed of the drill 6 by adjusting the flow control valve 30. can.

After adjusting the forward movement speed of the drill 6, when the operator presses the emergency return switch 38, the CPU 31 turns off the flashing display and sends an output signal to each circuit to reset all outputs. Output and return to initial state.

Next, when the operator presses the single-acting rotation operation switch 50 in order to know the rotational speed of the drill 6 before cutting, a single-acting rotation signal SG8 is output to the CPU 31. The CPU 31 responds to this signal SG8 and checks whether the same signal SG8 has been output 100 times to ensure completeness. Next, the CPU 31 once turns off all the signals output to each circuit, and then
A drive control signal for rotating the drill 6 is output to the motor drive circuit 37 in order to rotate only the motor 1.

At the same time as the drill 6 starts rotating, the display drive circuit 47 outputs a display control signal that lights up the leftmost display section 46a, and then the CPU 31 outputs a display control signal from the rotation detection circuit 48 every time the drill 6 rotates once. The value of the counter 49 which performs counting operation based on the pulse signal SG6 is input. When the value of the counter 49 reaches "10", that is, when the drill 6 has rotated 10 times, the CPU 31 resets the counter 49 and checks whether the rightmost display section 46j is lit.
At this point, the display section 46a is lit, so
The CPU 31 outputs a display control signal that turns off the display section 46a and lights up the display section 46b on the right side to the display drive circuit 47, and then outputs the display control signal to the display drive circuit 47 again.
Wait until the value becomes "10". And CPU3
1 repeats the same operation as above and displays the display parts 46a to 46a.
The lighting of 46j is made to shift sequentially from left to right. Eventually, when the drill 6 rotates 10 times with the rightmost display section 46j lit, the CPU 31 lights up the leftmost display section 46a again and repeats the same operation as described above. Therefore, the operator can know the rotation speed by measuring the time from when a predetermined display section lights up until it lights up again using a clock. In other words, if it takes 20 seconds to turn the light on again, the rotational speed of the drill 6 will be 300 (= 10 x 10 x
60/20) r・p・m can be easily and accurately determined.

After accurately knowing the rotational speed of the drill 6, when the operator presses the emergency return switch 38,
After stopping the motor 1, the CPU 31 returns to the initial state and waits for the next operation.

Next, from the state where the drill 6 is at the origin position in order to perform cutting on the workpiece 17, the operator turns on the start switch 3.
When 4 is pressed, a start signal SG1 is output to the CPU 31. After resetting the step counter 52 in response to the start signal SG1, the CPU 31 operates according to the flowchart shown in FIG. 8, and first outputs a forward rotation drive control signal to the motor drive circuit 37 to start the motor 1. After that, wait 0.5 seconds. This 0.5 second waiting period takes into account the time required for the motor 1 to reach a stable state with little fluctuation at the initial stage of rotation.

After 0.5 seconds have elapsed, the CPU 31 reads out the drive torque value [T0] in the no-load state at that time from the drive torque detection circuit 42 and stores it in addresses 1 and 3 of the RAM 33. Subsequently, the CPU 31 outputs a forward movement control signal to the valve drive circuit 45 to switch and control the electromagnetic valve 13 to move the drill 6 forward from the origin position P0 to the processing position. Then, the drill 6 starts forward movement, and the actuating piece 7b turns on the backward movement position detection switch SW2, thereby outputting a backward movement position signal SG from the backward movement position detection circuit 41.
5, the CPU 31 starts the step counter 52.
Outputs a count signal to.

When the drill 6 starts to move forward, the CPU 31 reads a new drive torque value [T] applied to the transmission spring 2 for each rotation during the forward movement from the drive torque detection circuit 42, and rewrites and stores it in address 2 of the RAM 33. At the same time, in order to obtain the cutting force [Tx] applied to the drill 6 for each rotation, a new drive torque value [T] for each rotation of the transmission spring 2 is stored in address 1 of the RAM 33 as the no-load drive torque value [ T0] executes the subtraction operation. Then, the CPU 31 calculates the cutting resistance [Tx] applied to the drill 6 for each rotation and the resistance reference value [X] read from the step torque value setting circuit 43.
1] and when it is determined that the cutting resistance [Tx] is smaller than the resistance reference value [X1],
The ratio of the cutting resistance [Tx] obtained for each rotation to the resistance reference value [X1] (hereinafter referred to as resistance ratio) [θ% (=[Tx]/[X1])] is calculated.
And CPU31 calculates this resistance ratio [θ%]
Based on this, a display control signal is output to the display drive circuit 47, and a number corresponding to the internal resistance ratio [θ%] of the ten display sections 46a to 46j are turned on sequentially from the display section 46a side. Therefore, the resistance ratio [θ%] is 30
%, the CPU 31 displays the display section 46a,
46b and 46c are turned on, and if it is 60%, the 6 from display part 46a to display part 46f is turned on.
light up. In addition, in this example, the resistance ratio [θ
%] is written as 31%, for example, the first digit is "1".
If there is a value of ~9, all values are rounded down to 30%, and three from the display section 46a to the display section 46c are displayed by lighting. Therefore, by simply observing the number of lit display sections among the display sections 46a to 46j, the operator can determine how much cutting force [Tx] currently being applied to the drill 6 is relative to the resistance reference value [X1]. You can easily find out what the percentage is.

Furthermore, the CPU 31 determines whether or not there is a breakage accident (an accident that occurs when the resistance reference value [X1] is set to a large value due to a setting error) due to an increase in the cutting resistance [Tx] of the drill 6 during forward movement of the drill 6. In order to do so, subtract the no-load drive torque value [T0] stored at address 3 of the RAM 33 by the new drive torque value T after the next rotation of the transmission spring 2,
Calculate the resistance reduction value [Z1]. And the CPU
31 sequentially compares the resistance reduction value [Z1] with the breakage reference value [Q] read from the drill breakage value setter 44 to determine whether or not the drill 6 has broken. If the drill 6 is not broken, the above-mentioned
Driving torque [T] stored in address 2 of RAM33
is rewritten to address 3 and stored. Therefore, RAM
Unless the drill 6 is broken, the contents stored in 33 are stored at address 2 after determining whether or not the drill 6 is broken.
It is rewritten to the drive torque [T] stored in . That is, the determination as to whether or not the drill 6 is broken is based on the fact that if the drill 6 is broken, the resistance reduction value [Z1] becomes 0 or a positive value.
Breakage of the drill 6 is determined by determining whether the resistance reduction value [Z1] is 0 or a positive value. In addition, in this example, the breakage reference value [Q]
You can set the value of 0 to 0, but drill 6
The cutting force [Tx] is not the reason for breakage, but
Since the torque may drop slightly during cutting for some reason, a desired positive value is set by the torque break value setter 43 in order to prevent malfunctions due to this.

Therefore, if the cutting force [Tx] applied to the drill 6 during cutting is less than the resistance reference value [X1], the CPU 31 continues the cutting process, and also controls the cutting force [Tx] applied to the drill 6 at that time. ] is displayed on the display sections 46a to 46j in proportion to the resistance reference value [X1].

Then, when the cutting resistance [Tx] of the drill 6 becomes larger than the resistance reference value [X1] during the cutting process with the drill 6 moving forward, the CPU
31 outputs a backward movement control signal to the valve drive circuit 45, and switches the electromagnetic valve 13 to immediately move the drill 6 back to the backward movement position R. and,
In response to the double motion position signal SG5 output from the double motion position detection circuit 41 when the drill 6 returns to the double motion position R, the CPU 31 detects the transmission spring 2 which is in the no-load state at that time, as described above. The drive torque value [T0] is read from the drive torque detection circuit 42, the previous contents are rewritten and stored in addresses 1 and 3 of the RAM 33, and the drill 6 is moved forward to start cutting again.

Thereafter, the CPU 31 repeats the same arithmetic processing operation as described above until the drill 6 reaches the machining end position where the cutting of the workpiece 17 is finished without breaking, and calculates the resistance ratio [θ%] at each time. The lighting control of the display sections 46a to 46j and the reciprocating movement control of the drill 6 are performed based on this control.

When the cutting of the workpiece 17 is completed and the drill 6 moves forward to the machining end position, the machining end detection circuit 40 outputs the end position signal SG4.
In response to this end position signal SG4, the CPU 31 outputs a light-off control signal to the display drive circuit 47 to turn off each display section 46a to 46j, and outputs a return control signal to the valve drive circuit 45,
The drill 6 is immediately moved back to return to the origin position P0. For CPU31, the drill 6 is the origin position P
By moving back to 0, a stop control signal is output to the motor drive circuit 37 in response to the origin position signal SG3 output from the origin position detection circuit 39, and the rotation of the motor 1 is stopped. and,
The machining is completed in preparation for cutting the next workpiece 17. Also, by looking at the display device 53 at this time,
You can check the number of steps (number of reciprocations) required for the cutting process.

On the other hand, due to the resistance reference value [X1] being set to a large value due to a setting error, the drill 6 was broken during the cutting process due to the cutting process proceeding without the drill 6 being moved back. When the resistance decrease value [Z1] is the breakage reference value [Q]
When the size of the drill 6 becomes larger than
The drive torque [T] that was applied to the transmission spring 2 of the drill 6 just before it broke, which is stored at address 1, and the drive torque [T0] in the no-load state, which is stored at address 1, are read out. Then, the CPU 31 converts the drive torque [T] into the drive torque [T] in the no-load state.
0] to obtain the breakage resistance Y1, and divide the breakage resistance Y1 by the resistance reference value [X1] to calculate the breakage resistance ratio [φ%]. That is, the ratio of the cutting resistance Y1 to the resistance reference value [X1] is calculated.
Next, the CPU 31 calculates this calculated breakage resistance ratio [φ
%], a display control signal is output to the display drive circuit 47, and the number of display parts 46 corresponding to the internal breakage resistance ratio [φ%] of the ten display parts 46a to 46j is
The display blinks in order from side a. Therefore, when the breakage resistance ratio [φ%] is 70%, the CPU 31 causes the seven displays from the display section 46a to the display section 46g to blink. This allows the operator to reduce the current resistance reference value [X1] by 30%,
Thereafter, the resistance reference value [X1] becomes accurate and reliable, and breakage accidents of the drill 6 can be prevented.

In this embodiment, the blinking display control of the display units 46a to 46j based on the breakage resistance ratio [φ%] is performed when the first digit is ``1'' to ``9'' such that the breakage resistance ratio [φ%] is 31%. ”, the value of that digit is rounded down to 30%, and the value is displayed from display section 46a to display section 46c.
The first three are made to blink to provide a margin of safety when modifying the resistance reference value [X1].

Subsequently, the CPU 31 outputs a backward movement signal to the valve drive circuit 45 to switch the electromagnetic valve 13, thereby causing the drill 6 to move backward to the home position P0. When the drill 6 returns to the home position P0 and the home position detection circuit 39 outputs the home position signal SG3,
In response to this origin position signal SG3, the CPU 31
A stop control signal is output to the motor drive circuit 37 to stop the motor 1.

Then, based on the stop of the motor 1, the operator replaces the drill 6 and the display parts 46a to 46a.
The resistance reference value [X1] is corrected by operating the step torque value setter 43 based on the number of flashing display parts 46j. Next, when the worker presses the emergency return switch 38, a reset signal SG2 is output to the CPU 31, and in response to this reset signal SG2, the CPU 31 turns off the flashing display and resets all circuits. After outputting the signal to start the process, a start signal SG is output from the start switch 34 to start cutting again.
Wait for 1.

As described above, in this embodiment, before cutting, the single-action feed operation switch 51 is operated to cause the drill 6 to perform only the feed operation, and the display sections 46a to 46j of the display 46 are displayed at predetermined intervals. The feed rate of the drill 6 can be easily checked by lighting up one by one in order to the right, and when the drill 6 reaches the machining end position, the display section that is lit at that time flashes. Not only can this be done, but it can also be seen at a glance that the drill 6 is located at the end of machining.

Also, before cutting, the single-acting rotary operation switch 50 is operated to drive the drill 6 only in rotation, and the display section 4 of the display 46 is turned on every predetermined rotation.
6a to 46j are lit up one by one in the right direction, and the time required for the display section to light up again is measured.
The rotation speed of can be easily checked.

Note that the present invention is not limited to the above-mentioned embodiment; for example, the CPU 31 may be caused to operate according to the flowchart shown in FIG. 9 based on the operation of the single-acting rotary operation switch 50. .

That is, the operator operates the single-acting rotary operation switch 50.
When the single-acting rotation signal SG8 is output to the CPU 31 by pressing , the same CPU 31 outputs the single-acting rotation signal SG8 in the same way as above.
After checking SG8, turn off all signals output to each circuit. Next, the CPU 31 outputs a drive control signal for rotating the drill 6 to the motor drive circuit 37 in order to rotate only the motor 1. After waiting for one second, the CPU 31 counts the number of pulse signals SG6 output from the one rotation detection circuit 48 for one second, and calculates the value "Nx".
Multiply by 60 to find the rotation speed "N" per minute.
At this time, all tens digits of the rotational speed "N" are rounded off, and the value of the rotational speed "N" is, for example,
Set the value to 900, 1500, 2100, 400, etc.

After calculating the value of rotation speed “N”, CPU31
After once all the display sections 46a to 46j are turned off, the display sections 46a to 46j are turned on from the left by the number of thousands digits of the rotational speed "N". For example, if the rotational speed "N" is 1500r・p・m, the display section 4
When 6a is 2000r/p/m, display section 46a,
The two on the left side of 46b are lit. Also, it does not light up when the rotational speed "N" is 900 r.p.m.

The CPU 31 displays the predetermined display sections 46a to 46j.
is displayed for one second, and then the display portions 46a to 46
j is turned off, and then the display sections 46a to 46j are turned on from the right side by the number of times corresponding to the hundreds place value of the rotational speed "N". For example, when the rotational speed "N" is 900 r.p.m., all the display sections 46b to 46j except the leftmost display section 46a are displayed, and when the rotation speed "N" is 1500 r.p.m., the right display sections 46f to 46j are displayed. Five are lit. Also, the rotational speed “N” is 2000r・p・m or
It will not light up at 4000rpm, etc.

Then, at the same time as this lighting, the CPU 31 again counts the number of pulse signals SG6 output per second, and determines the rotational speed of the drill 6 at that time "N".
After that, the same operation as above is repeated and the rotational speed "N" of the drill 6 at each time is displayed on the display 4.
6a to 46j.

Therefore, the operator first counts the number of display parts 46a to 46j that are lit up from the left to find out the value in the thousandth place of the rotational speed "N" of the drill 6, and then counts the number of display parts that are lit up and displayed from the right side. By counting the numbers 46a to 46j, the value of the rotational speed "N" in the hundreds place can be determined, and the rotational speed of the drill 6 can be easily determined.

Effects As detailed above, the present invention applies only rotational motion to the tool when the single-acting rotation operation switch is operated, and sequentially lights up the display part of the display every predetermined rotation of the tool, or A drive device that applies rotational force to the tool and an indicator are controlled by a control means so that each value of the value is sequentially lit from the top on the display part of the indicator in order to indicate the number of rotations at a predetermined time interval. Since it is controlled, the rotation speed of the tool can be easily checked in advance before machining.

Further, when the single-acting feed operation switch is operated, only reciprocating motion is applied to the tool, and the display part of the display is sequentially lit in one direction for a predetermined number of pieces at predetermined time intervals, and furthermore, the tool 6 completes the machining. The drive device and display for reciprocating the tool are controlled by the control means so that when the end is reached, the display that is lit at that time flashes, so the feed rate of the tool can be set in advance before machining. Not only can it be easily checked, but it can also be seen at a glance that the tool machining has reached the end.

[Brief explanation of drawings]

Fig. 1 is a mechanical diagram showing the mechanism of a drilling machine embodying this invention, Fig. 2 is an operating diagram of the step feed of the drill of this invention, Fig. 3 is a front view of the rotating disk, and Fig. 4 is a shielding plate. 5 is a side view showing the relative positional relationship between the rotating disk and the shielding plate, FIG. 6 is an electrical block circuit diagram, and FIGS. 7 and 8 explain the arithmetic processing operation of the central processing unit. FIG. 9 is a flowchart for explaining another embodiment of the present invention. Three-phase induction motor 1 as a rotational drive device, transmission spring 2, spline shaft 3, main shaft 4, drill 6 as a tool, main shaft cylinder 8, piston 9 as a reciprocating drive device, air cylinder 10, electromagnetic valve 1
3, air pump 14, workpiece 17, rotating disk 1
8, slit 19, shielding plate 21, photocoupler 25 for detecting angular displacement, central processing unit 31 as control means and detection means, read-only program memory 32, readable and writable memory 33 as storage means, starting switch 34, emergency return switch 38, drive torque setting device 43 as a torque detection device, drill breaking value setting device 44, display device 4
6. Display sections 46a to 46j, single-acting rotary operation switch 50, and single-acting feed operation switch 51.

Claims (1)

[Scope of Claims] 1. A machine tool in which the tool 6 is rotated relative to the workpiece 17 by the rotary drive device 1 and reciprocated relatively by the reciprocating drive devices 9 and 10 to perform processing, comprising: a single-acting rotary operation switch 50 that instructs the tool 6 to perform only rotational motion; a single-acting feed operation switch 51 that instructs the tool 6 to perform only the forward movement; and a plurality of display sections 46a to 46a. 46j are arranged in order, and when the single-acting rotary operation switch 50 is operated, the tool 6 is rotationally driven, and the display portions 46a to 46j of the display 46 are displayed every predetermined rotation of the tool 6.
or sequentially light up the respective values on the display sections 46a to 46j of the display device 46 from the top to indicate the number of rotations for each predetermined time,
When the single-acting feed operation switch 51 is operated, the tool 6 is moved forward and a predetermined number of display portions 46a to 46j of the display 46 are displayed at predetermined time intervals until the tool 6 reaches the machining end end of the workpiece 17. The drive devices 1, 9, 10 and the display 46 are controlled so that the display parts 46a to 46j that are lit at that time are turned on and off in one direction, and when the tool 6 reaches the machining end end, the display parts 46a to 46j that are lit at that time are made to blink. A machine tool comprising a control means 31 and the like.